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Biomedical subjects

D Newton

Publications and source records attributed to D Newton.

18 recordsLinked to original sources
PubMed1992

The weakness of old age is not due to failure of muscle activation.

Maximum voluntary force and cross-sectional area (MVF and CSA) of the human adductor pollicis muscle were compared in groups of young (19-55 years, mean = 28, n = 53) and elderly (74-90 years, mean = 80, n = 39) subjects, of both sexes. Despite the elderly subjects being in good health and active outdoors, they were considerably weaker than the young subjects, their MVF/CSA being 26 +/- 3% (mean +/- SEM) lower. It was found that both young and elderly subjects could fully activate their muscles. Therefore the muscle weakness of old age does not appear to be due to reduced activation and must be caused by another mechanism, possibly biochemical in nature.

Adult↗
PubMed1992

Elevation of lead in human blood from its controlled ingestion in beer.

1. Nine volunteers ingested high levels of lead in beer over a 28-d period. The increase in blood lead varied by a factor of about two. There was a similar two-fold variability in the whole-body uptake (mean 14%) of a single oral dose of the short-lived tracer 203Pb. 2. The average elevations led to estimates of the potential increment from consumption of alcoholic beverages which accord broadly with epidemiological observation and which, if relevant to intakes of lead in table wine, raise the possibility of considerably elevated levels in the blood of avid consumers. 3. Rate constants inferred for removal of stable lead from blood were lower than reported following intake of the tracer, reflecting feedback of lead from other compartments.

Adult↗
PubMed1977

Long-term haemodialysis and thyroid function.

Several indices of thyroid function were assessed in 74 patients with chronic renal failure. Sixty patients had undergone haemodialysis for varying periods. Within the first six months of haemodialysis treatment protein-bound iodine and total thyroxine (T4) levels rose, but after this T4 levels and the free thyroxine index fell progressively. Three out of the 12 patients who had undergone haemodialysis for longer than three years had subnormal T4 and supranormal thyrotrophin concentrations and a subnormal response to thyrotrophin stimulation. Lon-term haemodialysis may be a cause of biochemical hypothyroidism.

Humans↗
PubMed1977

Clearance of radioactive tantalum from the human lung after accidental inhalation.

Techniques of body radioactivity measurement were used to study the clearance of activated tantalum oxide accidentally inhaled by three reactor workers. The whole-body retention after 7 days was about 1% of the initial deposit. In one subject studied for a further 424 days the residual activity in the thorax was cleared with a biological half-life of about 1,400 days. The results support indications from other studies that tantalum powder administered in aerosol bronchography may be subject to prolonged alveolar retention.

Accidents↗